This invention relates to the field of hand tools, in particular a crowfoot. A crowfoot is a descriptive name used for a fixed-jaw, offset tool for tightening and loosening nuts, bolts and fittings in tight places. It is utilized by expert craftsmen to reach into inaccessible regions of heavy equipment and machinery, for example, where hex fittings, nuts and bolts, etc. are both difficult to reach and difficult to maneuver a tool around. In these situations, access is typically limited to utilizing an elongated rigid handle member (extension), to which there is removably attached a variation of sizes of fixed-jaw crowfeet. The craftsman simply selects out of his or her toolbox the appropriate metric or standard-sized crowfoot for the anticipated need, attaches it to the end of the elongated handle, inserts the handle and crowfoot attachment deep down into the machinery where needed, and twists and turns as necessary to loosen or tighten the respective nut, bolt or fitting.
This has several disadvantages and deficiencies. In particular, it requires an unusually high and burdensome number of tools inasmuch as a separate crowfoot is needed for each size of nut, bolt, or fitting available, in both metric and standard sizes. If one is working on an engine locomotive, an airplane engine or heavy sophisticated machinery of any kind, in house or in the field, there is a need for a single adjustable crowfoot that is not only relatively compact so as to fit in tight places while retaining its adjustable features, but is also easy to maneuver in tight places so that it is not only easy to turn while maximizing the force needed, but is somewhat self-adjusting so as to easily and automatically clamp and tighten onto the respective nut or bolt head in response to the operator""s turn, when the operator is sometimes several feet away from the respective nut or bolt. The instant invention not only achieves these objectives but is particularly well suited for those nuts, bolts and fittings of a hex or square variety.
A further problem relates to the need for the adjustable crowfoot to be removably attachable, yet sufficiently secured so as to essentially eliminate the risk of disengagement during use on heavy machinery. This is significant because the invention is particularly suited for the high level craft work on such things as engines, hydraulics, and other sophisticated machinery where it is not only important but in some cases governmentally required that the only tools that can be used are the disengagable type. Tools dropped in such sophisticated equipment cannot often be recovered without fully disassembling the equipment, an option that is not commonly or practically available on such equipment. Thus, is often the requirement for both practical and legal reasons, that all tools be pre-approved as the non-disengageable type.
Consequently, it is an object of the present invention not only to provide an adjustable crowfoot to substantially reduce the number of tools needed, but to provide such a crowfoot that is compact, maneuverable, easy and effective to use, relatively inexpensive to make, and is also reliable and utilizes the ability to lock and release on the respective fitting in direct response to the user, and further is non-disengagable. It is a further object that it be capable of accessing tight and hard to reach places, at a long distance utilizing an elongated rigid handle (extension) and that the crowfoot be adjustable from a distance.
The closest known device is disclosed in Schultz, U.S. Pat. No. 4,802,389. Schultz discloses and adjustable wrench that can be utilized with an extension as an adjustable crowfoot, however, Schultz""s device would not work to meet the objectives of the present invention inasmuch as the adjustable jaw member in Schultz is situated so as to prevent or hinder the tool""s accessing of the respective bolt, nut or fitting. To utilize the device in Schultz, one must approach the subject nut or bolt from the side. The present invention not only allows for a direct, hands-on approach to the bolt by the claws, but is far more precise; moreover, because the teeth of the rack in the instant invention are disposed away from the gripping area (just opposite to that shown in Schultz), the instant device allows for a precise, hex-shaped gripping area, the type of precision necessary to maximize the torque and gripping in extended and difficult to reach places. In short, the invention in Schultz would not work to achieve most of the objectives in the present invention.
Other objects and features of the invention and the manner in which the invention achieves its purpose will be appreciated from the foregoing and the following description and the accompanying drawings which exemplify the invention, it being understood that changes may be made in the specific method and apparatus disclosed herein without departing from the essentials of the invention set forth in the appended claims.